Pipe tongs

ABSTRACT

An adjustable pipe tong or clamp having a pair of jaw members adapted to clampingly engage a piece of pipe of a given size, said jaws being adapted to have mounted therein removable inserts of varying size which reduces the distance between the jaw members when closed to enable said tongs to grasp pipe of varying cross-sectional size.

United States Patent Fideldy 1 May 20, 1975 [54] PIPE TONGS 1,532,469 4/1925 Black 81/180 B 2,085,321 6/1937 Lang 269/270 x [76] Inventor: 2,553,802 5/1951 Woods 269/268X Bovey, 55709 2,592,803 4/1952 Heim 81/399 x 2,768,549 10/1956 Showers 81/399 [221 121973 3,545,315 12/1970 Patrick ..81/368 App]. No; 378,685

[52] U.S. Cl. 81/367; 81/423; 81/399 [51] Int. Cl. B25b 7/12 [58] Field of Search 81/367, 423, 422, 421, 81/425 R, 425 A, 377, 381, 399; 269/268, 269, 270

[56] References Cited UNITED STATES PATENTS 316,430 4/1885 Derby 81/423 465,959 12/1891 Yerdon 1. 269/270 X 1,350,671 8/1920 Sayres 81/180 B Primary Examiner-James L. Jones, Jr. Attorney, Agent, or FirmThomas A. Lennon ABSTRACT An adjustable pipe tong or clamp having a pair of jaw members adapted to clampingly engage a piece of pipe of a given size, said jaws being adapted to have mounted therein removable inserts of varying size which reduces the distance between the jaw members when closed to enable said tongs to grasp pipe of varying cross-sectional size.

2 Claims, 6 Drawing Figures PIPE TONGS Pipe tongs presently available are provided with a single pair of jaw members capable of grasping only a single size pipe, or are adjustable within a very limited range which will enable them to grasp another size pipe slightly larger or slightly smaller in diameter. However, the range of adjustment of presently available pipe tongs is very limited, requiring the operator to buy and have available a multiplicity of tongs of varying sizes to enable him to cope with any type of situation which he meets. These tongs are quite expensive and heavy and rather large in size, so that having to have a large number of these available is not only quite expensive, but also requires considerable additional space for storage and can add considerably to the amount of weight which must be carried and the number of trips which the operator must make from his truck to the job site.

Some of the tongs on the market also require continuous application of pressure on the handle to maintain a firm grip on the pipe by the jaws. This is tiresome for the operator and also means that he cannot leave the work momentarily or let go of the tongs without disengaging the tongs from the pipe.

The object of this invention is to provide a pipe tong which can be used with a much broader range of pipe sizes than has heretofore been possible, thereby minimizing the number of tongs which the operator must have available.

Another object is to provide pipe tongs with an automatic jaw locking system which enables the jaws to maintain a firm grip on the pipe after the handles have been moved to fully closed position, without having to maintain constant pressure thereon, and even when the operator lets go of the tongs.

Still another object is to provide a pipe tong with removable inserts for the'jaws of the tongs so that a wide range of sizes can be clamped or grasped by any set of tongs.

These and other objects and advantages will be apparent from a reading of the description and the accompanying drawing, wherein:

FIG. 1 is a side elevational view of one preferred embodiment of the pipe tong of this invention, with the jaws in closed clamping position and portions thereof broken away and with no removable inserts mounted in the basic jaw members.

FIG. 2 is a side elevational view of the invention corresponding to that shown in FIG. 1 with the jaws in unclamped open position;

FIG. 3 is a top plan view of the pipe tong of FIG. 1;

FIG. 4 is a cross-sectional view, taken along the line 44 of FIG, 5 of the tongs of FIG. 1 on an enlarged scale in closed clamping position, and with the removable inserts of this invention installed in the jaws thereof;

FIG. 5 is a longitudinal sectional view of the pipe tongs of FIG. 4 as taken along the line 5-5 of FIG. 4

and

FIG. 6 is a perspective view of one pair ofjaw inserts, or adaptors.

Reference is now made to the accompanying drawings for a better understanding of this invention. Referring first to the form of the invention without the inserts being used, the invention comprises a pair of cooperating handle structures which include jaw supporting arm sections 10 and 11 which are pivotally or hingedly connected by a hinge pin or bolt 12. The sections 10 and 11 respectively carry and support jaw members 13 and 14 which are curved in cross-section and are adapted to grasp therebetween the largest size pipe 15 for which these particular tongs are designed.

Each of the jaw supporting'sections 10 and 11 is provided with a manually graspable operating handle portion 16 and 17 respectively, the handle 16 being rigidly connected to its section 10 at the end thereof opposite that to which the jaw member 13 is attached.

The arm section 10 as illustrated comprises a pair of identically shaped opposed spaced apart plates which are rigidly interconnected at one end by handle 16 and at the other end by jaw 13, as by welding of the jaw and handle to the plates.

The other handle 17 is rigidly attached to a link 18 (consisting of a pair of spaced apart plates) which link in turn is hingedly connected to the arm 11 by means of a pivot bolt 19. The link 18 is in essence an intergral part of the handle 17 since it is rigidly secured thereto as by welding and moves simultaneously therewith. To enable the handle 17 to function properly and not interfere with or engage the handle 16, it is bent between the ends thereof so that the outer or free end portion is offset so that it will not encounter the handle 16 or any other part of the tong device when moved to the closed position, and so that it will assume a substantially parallel relationship with respect to the handle 16 in the closed clamping position as shown in FIG. 1, in which position the handles 16 and 17 are close enough together so that they can be simultaneously grasped in one hand, if desired.

To complete the linkage and connection of the jaw arm 11 with the jaw arm 10 still another link 20 is provided which is hingedly connected with handle 17 and arm 11 by means of a pivot pin 21, which pin or bolt hingedly connects the upper end of the link 20 to the link 19. One end portion of the link 20 is connected to the pivot bolt 21 and the end portion of link 20 adjacent bolt 21 is disposed between the two opposing bars of link 18 and operates therebetween.

The other end of the link 20 is provided with a slot 22 in which a limit or stop pin 23 is seated with the slot 22 moving relative to the pin 23, with the opposite ends of the slot 22 providing the range of movement in so far as the limit of the range of movement is concerned for that end of the link 20.

The arm portion 10 is, in the disclosed version. formed of opposed, identically shaped, spaced apart plate members with the end portion of the link 20 adjacent the pin 23 being disposed between the two plates. A small boss 24, having a threaded opening therein, is welded to the lower end of the arm 10, rigidly interconnecting the opposing plates thereof and a nut 25 is welded thereto and an adjusting screw 26 is threadedly inserted in the nut 25 and boss 24, with the inner end of the screw 26 being disposed between the two plate members forming the arm 10 with the inner end of the screw 26 being adapted to engage and limit the movement of the lower end of the link 20 as illustrated in FIG. 1. Thus, by adjusting the screw 26, the range of movement of the link 20, and, through the control of its movement the range of movement and gripping tension of the entire tongs, can be controlled. The more the screw 26 is inserted in the area between the plates 10, the smaller will be the space between the jaw members l3 and 14 and the more tightly the pipe will be gripped, or, conversely, the smaller the pipe that can be handled therebetween. The opposite is also true. If the screw is turned outwardly so as to Withdraw a greater portion thereof from the space between the plates 10, the result is a larger space between the jaw elements 13 and 14 and the accomodation of either a larger size pipe, or a looser grip.

Thus, in the form illustrated in FIGS. 13 inclusive, the tongs are initially placed in the open condition of FIG. 2 and the pipe 15 installed between the jaw members 13 and 14. It will be noted that the range of movement of the handle 17 away from 16 and towards the full open position is ultimately limited by the pin 23 engaging the lower end of the slot 22. After the pipe 15 is installed between the jaws, the handle 17 is then swung towards handle member 16. Initially the arm 11 does not move since the link 18 has a certain amount of lost motion before the arm 11 begins its travel. Initially the link 18 and the handle 17 pivot around the pivot 19 without movement by the arm 11 and in this initial situation, this pivotal movement around bolt 19 causes the link 20 to travel downwardly as shown in FIG. 2 until the lower end thereof abuts with the screw 26, thus terminating the travel of the link 20. At this point, the link 20 remains stationary and the link 18 and the handle 17 begin to pivot around the bolt 20, and in so doing causes the arm 11 to pivot about bolt 12 towards a closed clamping position, until the three pivot points 12, 19 and 21 are in alignment with one another. Continued movement of the handle 17 towards the handle 16 then causes the middle bolt 19 to pass center and move upwardly and in so doing draws the pivot bolt 21 and the link 20 towards the arms 10 until it reaches a fully closed clamping position of FIG. 1.

In order to accomodate pipe sizes smaller than pipe 15, the invention contemplates the use of removable inserts or adaptors best illustrated in FIG. 6. These inserts are identical and are identified by the numeral 27. Each of these inserts 27 is arcuate in cross-section and of a curvature similar to the jaw members 13 and 14, so that they can mate therewith when they are installed therein. Each of these inserts 27 is provided with an anchoring pin or stud 28 which is provided with a small transverse opening 29.

Each of the jaw members 13 and 14 is provided with a transverse hole or opening 30 in which the pins 38 of the inserts are installed. FIGS. 4 and 5 best illustrate the installation of the inserts in the tongs. After the inserts are installed and the pins have passed through the openings 30 and 33 of the jaws, removable retaining means such as cotter pins 31 are installed in each of the openings 29 of the mounting pins 28 to removably hold the inserts in position on the jaw members. FIG. 4 shows the inserts mounted in the jaws and in clamping relationship with a piece of pipe 32. Once the inserts are installed in the jaws, the operation of the tongs is as previously described above for the version illustrated in FIGS. 1-3 inclusive. It will be appreciated that inserts of different cross-sectional thickness can be used to accomodate an almost infinite variety of sizes of pipe, particularly when one considers that there is a certain range of adjustment provided by the screw 26 so that between the screw 26 and the variety of inserts which may be used, that the tongs of this invention can be used with many different sizes of pipes.

The tongs have an over-center or toggle type locking action which takes place when the pivot pin 21 has moved from an open jaw position such as in FIG. 2

downwardly and inwardly past an imaginary straight line passing through the axis of bolt 19 and the point of contact of the link 20 with the adjusting screw 26.

The adaptors are so designed that the opposite halves are usable on either side, so that there are no right hand and left hand inserts. Thus, only one kind of insert need be made reducing the tooling costs and reducing the number of kinds of inserts to be stocked, replaced or carried in inventory.

It will also be noted that the inserts can be readily and conveniently installed and removed without disassemblying any other parts of the tongs and that the tongs are so designed that they can be readily adjusted to grasp any part or section of a length of pipe. It will, of course, be understood that the description and drawings illustrate only several embodiments of the invention and that the invention is broader in scope and contemplation than what is herein described and illustrated, the invention being limited only by the claims hereof.

The embodiments of this invention in which an exclusive property or privilege is claimed are defined as follows:

1. A pipe clamping device comprising a pair of jaw members, each of said jaw members having a concavely curved pipe engaging face,

handle means for opening and closing said jaw members for enclosing and gripping a pipe of predetermined diameter therebetween,

each of said faces having a transverse opening formed therein and extending completely through its respective jaw member, an adaptor for each of said faces, each of said adaptors being arcuate in cross section and having inner and outer walls of corresponding curvature, both of said walls having a curvature corresponding to the curvature of the faces of said jaw members, the inner wall being adapted to engage the face of its respective jaw member, the outer face being adapted to engage and hold a pipe having a diameter smaller than said predetermined diameter,

each adaptor having a mounting pin integrally formed therewith and extending transversely from the inner wall,

said mounting pin being insertable in said opening of said jaw member and extendable completely through said jaw member so as to extend outwardly from said jaw member,

. a portion of said mounting pin which extends outwardly from said jaw member being adapted to be engaged by a retaining element,

and a retaining element engageable with said portion of said mounting pin for removably holding said adaptor on said jaw member,

each of said adaptors being interchangeably mountable on either of said jaw members.

2. A pipe clamping device comprising a pair of jaw members, each of said jaw members having a concave curved pipe engaging face for grasping and holding a section of pipe between said jaw members,

one of said jaw members being mounted on and supported by first handle structure which includes a manually graspable handle section having one of said jaw members mounted on one end thereof and having a manually graspable handle section at the other end thereof,

second handle structure which includes a first section on which the other of said jaw members is mounted, said first section being pivotally connected to said first handle structure for relative movement therebetween for opening and closing said jaw members,

said second handle structure including a second section having one end thereof pivotally connected to said first handle section,

an elongate link extending between said first and second handle structures,

one end of said link being pivotally connected to said second handle section,

the other end of said link having an elongate slot formed therein,

said slot being adapted to control the direction of movement of said link between jaw locking and jaw releasing position,

pin means carried by said first handle structure and, installed in said slot whereby said link is movable relative to said first handle structure and said pin with the direction of movement of said other end of said link being guided and controlled by said pin,

said other end of said link having a cam surface,

an adjusting screw carried by said first handle structure and movable towards and away from the cam surface of said link in response to the turning of said adjusting screw,

said adjusting screw being adapted to be engaged by said cam surface to limit the downward movement of said other end of said link as said second handle structure is moved from jaw opening to jaw closing position,

the pivot axis between said one end of said link and said second handle structure being disposed on one side of a line extending through the point of contact between said cam surface and said adjusting screw and the pivot axis between the first and second sections of said second handle structure when said jaw members are unlocked,

continued movement of said second handle structure towards jaw closing position moving said pivot axis between said link and said second handle section to the other side of said line to provide an over-center locking action which locks said jaw members in engagement with pipe disposed therebetween. 

1. A pipe clamping device comprising a pair of jaw members, each of said jaw members having a concavely curved pipe engaging face, handle means for opening and closing said jaw members for enclosing and gripping a pipe of predetermined diameter therebetween, each of said faces having a transverse opening formed therein and extending completely through its respective jaw member, an adaptor for each of said faces, each of said adaptors being arcuate in cross section and having inner and outer walls of corresponding curvature, both of said walls having a curvature corresponding to the curvature of the faces of said jaw members, the inner wall being adapted to engage the face of its respective jaw member, the outer face being adapted to engage and hold a pipe having a diameter smaller than said predetermined diameter, each adaptor having a mounting pin integrally formed therewith and extending transversely from the inner wall, said mounting pin being insertable in said opening of said jaw member and extendable completely through said jaw member so as to extend outwardly from said jaw member, a portion of said mounting pin which extends outwardly from said jaw member being adapted to be engaged by a retaining element, and a retaining element engageable with said portion of said mounting pin for removably holding said adaptor on said jaw member, each of said adaptors being interchangeably mountable on either of said jaw members.
 2. A pipe clamping device comprising a pair of jaw members, each of said jaw members having a concave curved pipe engaging face for grasping and holding a section of pipe between said jaw members, one of said jaw members being mounted on and supported by first handle structure which includes a manually graspable handle section having one of said jaw members mounted on one end thereof and having a manually graspable handle section at the other end thereof, second handle structure which includes a first section on which the other of said jaw members is mounted, said first section being pivotally connected to said first handle structure for relative movement therebetween for opening and closing said jaw members, said second handle structure including a second section having one end thereof pivotally connected to said first handle section, an elongate link extending between said first and second handle structures, one end of said link being pivotally connected to said second handle section, the other end of said link having an elongate slot formed therein, said slot being adapted to control the direction of movement of said link between jaw locking and jaw releasing position, pin means carried by said first handle structure and installed in said slot whereby said link is movable relative to said first handle structure and said pin with the direction of movement of said other end of said link being guided and controlled by said pin, said other end of said link having a cam surface, an adjusting screw carried by said first handle structure and movable towards and away from the cam surface of said link in response to the turning of said adjusting screw, said adjusting screw being adapted to be engaged by said cam surface to limit the downward movement of said other end of said link as said second handle structure is moved from jaw opening to jaw closing position, the pivot axis between said one end of said link and said second handle structure being dIsposed on one side of a line extending through the point of contact between said cam surface and said adjusting screw and the pivot axis between the first and second sections of said second handle structure when said jaw members are unlocked, continued movement of said second handle structure towards jaw closing position moving said pivot axis between said link and said second handle section to the other side of said line to provide an over-center locking action which locks said jaw members in engagement with pipe disposed therebetween. 